In the manufacture of fiber from molten material, such as molten glass, it has been common practice to use a bushing made of precious metals including platinum, rhodium, palladium, ruthenium, iridium and alloys thereof. The bushings are electrically heated by their own resistance and are box-like, open on the top and comprise an orifice plate containing hundreds or thousands of nozzles or tips welded or punched thereon as shown by U.S. Pat. Nos. 4,207,086 and 4,078,413, which disclosures are hereby incorporated by reference.
As the molten material emerges from the orifices or nozzles, a meniscus of molten material is formed below each orifice or tip from which a fiber is pulled continuously. This is the objective, but if the temperature of the meniscus is not carefully controlled, one or more fibers break, requiring a costly stoppage of fiberization from that bushing and a restart of the bushing. To remove the heat that must be removed to cool the molten fiber so that it will have integrity and strength to pull the formed fiber behind, cooling members are located close to the orifices or nozzle tips to remove heat from the meniscus and newly formed fiber. These cooling members can be either cooling tubes like shown in U.S. Pat. Nos. 4,397,665, 5,244,483 and 6,196,029, the disclosures of which are hereby incorporated by reference, or cooling fins as are well known in the fiber industry.
Because it is not possible to maintain a uniform temperature across all of the nozzles or orifices using only the bushing, it is conventional to adjust the cooling tubes or fins individually and as a group to address hot spots, cold corners, and other fiber forming temperature problems. Bushings continue to get larger with thousands of nozzles or orifices creating or exaggerating temperature non-uniformities versus smaller bushings of the past. Past apparatus for adjusting the cooling members has been cumbersome and difficult to position the cooling members precisely to maintain the desired spacing between the cooling members and the tip plate or orifice plate, the tips, the molten glass meniscuses beneath the tips or orifices and the just formed fibers. This spacing is extremely important because at the temperatures the tips and meniscuses are at during fiberization, the heat transfer is dependent upon the square of the separation distance. It is very hot and uncomfortable around the bottom bushing and bushing mounting frame that holds the bushing in place. To insure that the cooling members are optimally positioned, it is important that the adjusting means is easy to use and to quickly and precisely position the cooling members. To achieve accurate positioning in this hot corrosive environment it is also important for the adjusting apparatus to be simple with none or few moving parts. Current adjustable support apparatus exists for adjusting the cooling members vertically, but is severely lacking in the these requirements and in enabling adjustment of the each tube laterally towards or away from the exit end of the tips and the meniscus.